SYSTEM ADMINISTRATION MTAT.08.021 LECTURE 7 NETWORK MANAGEMENT AND DEBUGGING Prepared By: Amnir Hadachi and Artjom Lind University of Tartu, Institute of Computer Science
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[email protected] 1 LECTURE 7: NETWORK MGT AND DEBUGGING OUTLINE 1.Intro 2.Network Troubleshooting 3.Ping 4.SmokePing 5.Trace route 6.Network statistics 7.Inspection of live interface activity 8.Packet sniffers 9.Network management protocols 10.Network mapper 2 1. INTRO 3 LECTURE 7: NETWORK MGT AND DEBUGGING INTRO QUOTE: Networks has tendency to increase the number of interdependencies among machine; therefore, they tend to magnify problems. • Network management tasks: ✴ Fault detection for networks, gateways, and critical servers ✴ Schemes for notifying an administrator of problems ✴ General network monitoring, to balance load and plan expansion ✴ Documentation and visualization of the network ✴ Administration of network devices from a central site 4 LECTURE 7: NETWORK MGT AND DEBUGGING INTRO Network Size 160 120 80 40 Management Procedures 0 AUTOMATION ILLUSTRATION OF NETWORK GROWTH VS MGT PROCEDURES AUTOMATION 5 LECTURE 7: NETWORK MGT AND DEBUGGING INTRO • Network: • Subnets + Routers / switches Time to consider • Automating mgt tasks: • shell scripting source: http://www.eventhelix.com/RealtimeMantra/Networking/ip_routing.htm#.VvjkA2MQhIY • network mgt station 6 2. NETWORK TROUBLES HOOTING 7 LECTURE 7: NETWORK MGT AND DEBUGGING NETWORK TROUBLESHOOTING • Many tools are available for debugging • Debugging: • Low-level (e.g. TCP/IP layer) • high-level (e.g. DNS, NFS, and HTTP) • This section progress: ping trace route GENERAL ESSENTIAL TROUBLESHOOTING netstat TOOLS STRATEGY nmap tcpdump … 8 LECTURE 7: NETWORK MGT AND DEBUGGING NETWORK TROUBLESHOOTING • Before action, principle to consider: ✴ Make one change at a time ✴ Document the situation as it was before you got involved.